eiac/crypto
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ssh: ignore MAC if AEAD ciphers negotiated

Browse Source 
If the server/client cipher chosen is one of the two AEAD ciphers that
we support (aes128-gcm@openssh.com and chacha20-poly1305@openssh.com),
don't attempt to find a common MAC algorithm in findAgreedAlgorithms.
Similarly in newPacketCipher, don't attempt to generate a MAC key if we
are using a AEAD cipher.

Fixes golang/go#51406

Change-Id: Id48ae72f052cb0a0c597b32e9901a0f218e4161f
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/389214
Trust: Roland Shoemaker <roland@golang.org>
Run-TryBot: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
This commit is contained in:
Roland Shoemaker
2022-03-12 13:11:42 +00:00
committed by Filippo Valsorda
parent efcb8507fb
commit 6068a2e6cf
3 changed files with 45 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ssh/transport.go
+7 -3
View File
@@ -238,15 +238,19 @@ var (
// (to setup server->client keys) or clientKeys (for client->server keys).
func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (packetCipher, error) {
cipherMode := cipherModes[algs.Cipher]
macMode := macModes[algs.MAC]
iv := make([]byte, cipherMode.ivSize)
key := make([]byte, cipherMode.keySize)
macKey := make([]byte, macMode.keySize)
generateKeyMaterial(iv, d.ivTag, kex)
generateKeyMaterial(key, d.keyTag, kex)
generateKeyMaterial(macKey, d.macKeyTag, kex)
var macKey []byte
if !aeadCiphers[algs.Cipher] {
macMode := macModes[algs.MAC]
macKey = make([]byte, macMode.keySize)
generateKeyMaterial(macKey, d.macKeyTag, kex)
}
return cipherModes[algs.Cipher].create(key, iv, macKey, algs)
}